There is a growing interest in the potential of pulse mode CdZnTe crystalline detectors for high-flux high-speed energy selective or hyper-spectral x-ray imaging. The energy sensitivity provided by the Cd1-xZnxTe, where (0≦x<1), material forming these detectors opens up a range of new potential applications for this detector technology in medical, industrial, security imaging and tomography. In fact, such energy sensitivity can potentially revolutionize these fields. However, imaging applications typically require photon flux fields that generate very high count rates within the CdZnTe detector. For example, medical Computed Tomography applications represent a large potential market for this technology, but require CdZnTe detectors capable of handling count rates from 20 to 2000 million counts per second per square millimeter (counts/s/mm2).
One of the challenges in applying pulse mode CdZnTe detectors to applications requiring such high count rates is avoiding a build up of “space charge” within the CdZnTe crystal structure that collapses the electric field and results in a reversible count paralyzation failure (i.e., polarization). Therefore, these CdZnTe detectors must be designed such that charge generated by photon flux, e.g., x-ray radiation, in the CdZnTe crystal structure thereof is dissipated at a sufficiently high rate, through both drift and recombination, to avoid polarization. Proper selection of both the quality of the CdZnTe material forming such detector and the CdZnTe detector's design parameters are paramount to achieving high charge throughput for such detectors while avoiding polarization.